Re: [PATCH] thermal: sun8i: Be loud when probe fails

From: Maxime Ripard <maxime@cerno.tech>
To: Ondrej Jirman <megous@megous.com>
Cc: linux-sunxi@googlegroups.com,
	Vasily Khoruzhick <anarsoul@gmail.com>,
	Yangtao Li <tiny.windzz@gmail.com>,
	Zhang Rui <rui.zhang@intel.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Kucheria <amit.kucheria@verdurent.com>,
	Chen-Yu Tsai <wens@csie.org>,
	"open list:ALLWINNER THERMAL DRIVER" <linux-pm@vger.kernel.org>,
	"moderated list:ARM/Allwinner sunXi SoC support" 
	<linux-arm-kernel@lists.infradead.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] thermal: sun8i: Be loud when probe fails
Date: Wed, 8 Jul 2020 14:25:42 +0200	[thread overview]
Message-ID: <20200708122542.73o3lbhgvbdw5c4z@gilmour.lan> (raw)
In-Reply-To: <20200708105527.868987-1-megous@megous.com>

Hi,

On Wed, Jul 08, 2020 at 12:55:27PM +0200, Ondrej Jirman wrote:
> I noticed several mobile Linux distributions failing to enable the
> thermal regulation correctly, because the kernel is silent
> when thermal driver fails to probe. Add enough error reporting
> to debug issues and warn users in case thermal sensor is failing
> to probe.
> 
> Failing to notify users means, that SoC can easily overheat under
> load.
> 
> Signed-off-by: Ondrej Jirman <megous@megous.com>
> ---
>  drivers/thermal/sun8i_thermal.c | 55 ++++++++++++++++++++++++++-------
>  1 file changed, 43 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c
> index 74d73be16496..9065e79ae743 100644
> --- a/drivers/thermal/sun8i_thermal.c
> +++ b/drivers/thermal/sun8i_thermal.c
> @@ -287,8 +287,12 @@ static int sun8i_ths_calibrate(struct ths_device *tmdev)
>  
>  	calcell = devm_nvmem_cell_get(dev, "calibration");
>  	if (IS_ERR(calcell)) {
> +		dev_err(dev, "Failed to get calibration nvmem cell (%ld)\n",
> +			PTR_ERR(calcell));
> +
>  		if (PTR_ERR(calcell) == -EPROBE_DEFER)
>  			return -EPROBE_DEFER;
> +

The rest of the patch makes sense, but we should probably put the error
message after the EPROBE_DEFER return so that we don't print any extra
noise that isn't necessarily useful

Maxime